SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cea4393db3fb6d89e82f2e93e845f1dcc11a5eed0fa38626b39ac349d460e267' 
  AND token = 'nmWr3eaADCM1rIS+NFPcV/qlcLbHtEQXWSKOYDHhQ1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}